I have no idea how anyone would define best midrange, much less, best midrange in the mind of someone else. All I can say is that I have heard, and liked the Aero Capitole, I use to own the SCD-1, and I currently own a Naim CD555. I like what the Naim does, overall, but, I can't say it is because of any particular strength, such as the midrange.
I also like, very much, DACs from Audionote. I know a number of people with DAC5s (really expensive), and one person who built their top-of-the-line kit (including all upgraded parts). That DAC is really good, particularly at the price of the unbuilt kit. The sound is very relaxed, natural, and warm without being sluggish and without rounding off detail, attack or upper frequency "air."